Applying the Concepts Ch. 10

16. Any substance that contains avogadro's number is called a (an) a. Mole. B, atomic number. C. Gopher. D. Pound.

a. Mole.

48. What is the empirical formua of butane, C4H10? a. CH b. C2H5 c. CH3 d. C4H10

b. C2H5

31. The incomplete equation of 2 KC1O3(s) —+ probably represents which type of chemical reaction? a. Combination b. Decomposition c. Replacement d. Ion exchange

b. Decomposition

41. How many sodium atoms are in 2 moles of sodium? a. 11 b. 6.02 x 1023 c. 1.20 x 1024 d. 22

c. 1.20 x 1024

40. How many liters of propane gas are needed to produce 16 L of water vapour? C3H8(g) + 5 O2 🡪 3 CO2(g) + 4 H2O(g) a. 2 b. 3 c. 4 d. 16

c. 4

9. To what chemical reaction class does this reaction belong? CaCO3(s) --> CaO(s) + CO2(g) a. Combination b. Ion exchange c. Decomposition d. Replacement

c. Decomposition

12. Which is the most active metal? a. Silver b. Lead c. Zinc d. Sodium

d. Sodium

30. You know that an expected ion exchange reaction has taken place if the products include a. a precipitate. b. a gas. c. water. d. any of the above.

d. any of the above.

36. What are the coefficients needed to balance this chemical equation? __CaCl2 + __KOH 🡪 __Ca(OH)2 + KCl a. 1, 2, 1, 2 b. 2, 1, 2, 1 c. 1, 1, 1, 2 d. 2, 1, 1, 1

a. 1, 2, 1, 2

6. What products are formed from the complete reaction of hydrocarbons or carbohydrates with oxygen? a. CO2 + H2O b. CO + H2O c. CH, + CO2 d. CO2 + H2

a. CO2 + H2O

17. A material that speeds up a chemical reaction without being permanently changed by the reaction is a (an) a. Catalyst. B. Reactant. C. Product. D. Active metal.

a. Catalyst.

10. To what chemical reaction class does this reaction belong? 2 Mg(s) + 02(g) —> 2 MgO(s) a. Combination b. Ion exchange c. Decomposition d. Replacement

a. Combination

18. The most active metals are found in group a. IA. B. IIA. C. IB. D. IIB.

a. IA.

4. What is the meaning of the subscripts in a chemical formula? a. Number of atoms of an element in a compound b. Percent composition of that element in a compound c. Number of molecules of that compound d. Number of molecules in the reaction

a. Number of atoms of an element in a compound

29. Of the following elements, the one with the greatest chemical activity is a. aluminum. b. zinc. c. iron. d. mercury.

a. aluminum.

25. When carbon burns with an insufficient supply of oxygen, carbon monoxide is formed according to the following equation 2 C + O2 🡪 2 CO. What category of chemical reaction is this? a. combination b. ion exchange c. replacement d. none of the above is correct because the reaction is incomplete

a. combination

7. In a redox reaction, reduction is defined as the a. gain of electrons by an atom. b. loss of mass of an atom. c. loss of electrons by an atom. d. gain of mass of an atom.

a. gain of electrons by an atom.

3. The sum of the atomic weights of all atoms in the ammonia molecule, NH3, is called a. molecular weight. b. gravity weight. c. periodic weight. d. percent weight.

a. molecular weight.

11. Substances that take electrons from other substances are called a. oxidizing agents. b. reducing agents. c. ions. d. compounds.

a. oxidizing agents.

13. A solid that comes out of solution as a result of an ion exchange reaction is called a a. precipitate. b. contaminant. c. base. d. metal.

a. precipitate.

14. A balanced chemical equation provides quantitative information about all of the following except a. time of reaction. b. atoms. c. molecules. d. atomic weights of reactants and products

a. time of reaction.

49. How many moles of products are in this chemical equation? CH4g) + 2 O2(g) 🡪 CO2 (g) + 2 H2O(g) a. 2 b. 3 c. 6 d. 6.02 x 1023

b. 3

38. Which reaction is an example of a combination reaction? a. 2 HgO(s) 🡪 2 Hg(s) + O2(g) b. 4 Fe(s) + 3O2(s) 🡪 Fe2O3(g) c. CaC03(s) 🡪 CaCO(s) + CO2 (g) d. Na(s) + KCl(aq) 🡪 K(s) +NaCl(aq)

b. 4 Fe(s) + 3O2(s) 🡪 Fe2O3(g)

45. What is the formula weight of magnesium hydroxide, an ingredient found in antacids? a. 41.3 u b. 58.3 u c. 72. 0 u d. 89.0 u

b. 58.3 u

24. Since wood is composed of carbohydrates, you should expect which gases to exhaust from a fireplace when complete combustion takes place? A. Carbon dioxide, carbon monoxide, and pollutants b. Carbon dioxide and water vapor C. Carbon monoxide and smoke D. It depends on the type of wood being burned.

b. Carbon dioxide and water vapor

44 The iron in a scouring pad will react with oxygen in the air to form iron oxide, Fe2O3 rust. The type of reaction that is described is a. replacement b. combination c. decomposition d. ion exchange

b. combination

1. An empirical formula does not a. identify elements in a compound. b. identify actual numbers of atoms in a molecule. c. provide the simplest whole number ratio of atoms of elements with subscripts. d. provide the formula for an ionic compound.

b. identify actual numbers of atoms in a molecule.

5. "Atoms are neither created nor destroyed in a chemical reaction" is a statement of the a. law of definite proportions. b. law of conservation of mass. c. law of percent composition. d. atomic theory.

b. law of conservation of mass.

2. The relative arrangement of the atoms in a molecule is a (an) a. empirical formula. b. structural formula. c. molecular formula. d. covalent formula.

b. structural formula.

27. In a replacement reaction, elements that have the greatest ability to hold onto their electrons are a. the most chemically active. b. the least chemically active. c. not generally involved in replacement reaction d. None of the above is correct.

b. the least chemically active.

33. If you have 6.02 X 1023 atoms of metallic iron, you will have bow many grams of iron? a. 26 b.55.85 c. 334.8 d. 3.4 X 1025

b.55.85

47. What are the coefficients needed to balance this chemical equation? __C2Hg(g) + __ O2 (g) 🡪 __CO2(g) + __H2O(g) a. 1, 3, 2, 3 b. 1, 5, 2, 3 c. 2, 7, 4, 6 d. 2, 5, 4, 3

c. 2, 7, 4, 6

42. What is the gram-based formula weight of sodium chloride? a. 23 u b. 23 g c. 5 g d. 5u

c. 5 g

15. the number of atoms in exactly 12.00 g of C-12 is called A. Atomic number. B. Atomic weight. c. Avogadro's number. D. Molecular number.

c. Avogadro's number.

37. What class of chemical reactions is not considered to belong to the class of oxidation-reduction reactions? a. Combination b. Decomposition c. Ion exchange d. Replacement

c. Ion exchange

19. Potassium reacts with water to form potassium hydroxide and hydrogen gas. What kind of reaction is this? A. Decomposition B. Combination c. Replacement D. Ion exchange

c. Replacement

39. To what chemical reaction class does this reaction belong? Fe(s) + CuSO4(aq) 🡪 Cu(s) + FeSO4(aq) a. Ion exchange b. Combination c. Replacement d. Decomposition

c. Replacement

21. A balanced chemical equation has A. The same number of molecules on both sides of the equation B. The same kinds of molecules on both sides of the equation c. The same number of each kind of atom on both sides of the equation. D. All of the above.

c. The same number of each kind of atom on both sides of the equation.

8. In a redox reaction, oxidation is defined as the a. gain of electrons by an atom. b. loss of mass of an atom. c. loss of electrons by an atom. d. gain of mass of an atom.

c. loss of electrons by an atom.

32. In the equation 2 I-12(g) + 02(g) --> 2 H2O( 1) a. the total mass of the gaseous reactants is less than the total mass of the liquid product. b. the total number of molecules in the reactants is equal to the total number of molecules in the products. c. one volume of oxygen combines with two volumes of hydrogen to produce two volumes of water. d. All of the above are correct.

c. one volume of oxygen combines with two volumes of hydrogen to produce two volumes of water.

35. What is the formula weight of acetic acid, CH3COOH, which is found in vinegar? a. 20.0 u b. 48.0 u c. 58.0 u d. 60.0 u

d. 60.0 u

34. The molecular formula of Benzene, C6H6, tells us that benzene is composed of six carbon atoms and six hydrogen atoms. What is the empirical formula of benzene? a. C3H3 b. C6H6 c. C2H2 d. CH

d. CH

43. A balanced chemical reaction provides all of the following information except a. molecular ratio of reactants and products b. mole ratio of reactants and products c. mass ratio of reactants and products d. exchange rate of reactants and products

d. exchange rate of reactants and products

26. According to the activity series for metals, adding metallic iron to a solution of aluminum chloride should result in a. a solution of iron chloride and metallic aluminum b. a mixed solution of irony and aluminum chloride c. the formation of iron hydroxide with hydrogen given off d. no metal replacement reaction.

d. no metal replacement reaction.

28. Of the following elements, the one with the greatest electron holding ability is a. sodium. b. zinc. c. copper_ d. platinum.

d. platinum.

46. An ion exchange reaction can be identified by all of the following except a. formation of a precipitate b. generation of a gas c. formation of water d. the required addition of heat

d. the required addition of heat

22. The law of conservation of mass means that A. Atoms are not lost or destroyed in a chemical reaction. B. The mass of a newly formed compound cannot be changed. C. In burning, part of the mass must be converted into fire in order for mass to be conserved. D. Molecules cannot be broken apart because this would result in less mass.

A. Atoms are not lost or destroyed in a chemical reaction.

20. The molecular weight of sulfuric acid, H2SO4, is a. 49 u. B. 50 u. C. 98 u. D. 194 u.

C. 98 u.

23. A chemical equation is balanced by changing A. Subscripts. B. Superscripts. C. Coefficients. D. Any of the above is correct as necessary to achieve a balance.

C. Coefficients.